Cristina Speirs, 22, was a self-proclaimed "health freak" during her senior year of college, which is all the more reason she would have never guessed that her body would betray her the way it did.

She exercised six times a week, taught hot yoga classes and drank a lot of water throughout the day to stay hydrated. So, when she stopped feeling tired and started getting up more frequently in the middle of the night to go to the bathroom, she didn't think anything of it.

"I had a lot of energy," Speirs said. "I wasn't sleeping. ... I was always on the go. I was never tired."

She would eventually learn that she had a tumor the size of an orange on her adrenal gland, and that it was making the hormones that kept her up at night.

Doctors first noticed a problem at Speirs' annual checkup in the fall of 2012 when they found that her potassium levels were low, but her blood pressure was "through the roof."

But they had no idea what was causing the strange symptoms.

"That really freaked me out because them not knowing what's wrong with me -- they're doctors, you know?" Speirs said.

A cardiologist quickly determined there was nothing wrong with her heart, but Speirs' mother suggested a renal sonogram to check her kidneys.

Speirs noticed that the sonogram technician spent a long time lingering over her kidneys and looked confused. Alarmed, Speirs asked what was wrong. The technician told Speirs she needed an MRI right away because she suspected Speirs had one large combined kidney instead of two normal-sized kidneys.

The MRI would reveal that Speirs had normal kidneys. It was a 10-centimeter tumor that the technician was seeing.

"I was in complete shock," she said, explaining that she phoned her parents immediately to tell them that she'd need surgery. "Then, I got so upset honestly. I had no idea where this came from."

Then she met Dr. William Inabnet, co-director of the Adrenal Center at Mount Sinai Hospital in New York City. Upon learning that Speirs' tumor was producing two hormones -- cortisol and aldosterone -- he feared that the tumor was cancerous.

On Oct. 18, 2012, he scheduled surgery to remove it the following Halloween. Surgery on the spooky holiday made Speirs feel superstitious, but she didn't say anything.

And then Superstorm Sandy hit on Oct. 29, and the hospital was thrown into chaos. Evacuated patients from NYU Langone Medical Center were sent to Mount Sinai, and doctors from different hospitals were working side by side to help the sickest patients.

The hospital was packed, and most regular surgeries were canceled.

"We had to really negotiate and find a team that could staff the case," Inabnet said, adding that he needed nurses, anesthesiologists and others to operate.

Speirs' parents kept the reality of the storm mostly hidden from her, but before she handed her glasses to her father to be wheeled off into the operating room, she saw all the beds of patients displaced by Sandy.

"I was just kind of a little teary," she said, remembering the cold of the operating room and the little warmth offered by the hospital gown.